The present invention relates to fluid monitors, particularly for monitoring fluid flowing through a flow path.
In many industrial systems, it is necessary or desirable to be able to monitor the temperature and/or rate of flow of fluid flowing along a flow path. For example, in the case of water cooled generator stators, it is necessary to monitor the temperature of the water being used to cool the stator coils.
It is known to monitor the temperature of the cooling water of generator stator coils by means of a thermocouple which is mounted on the outer surface of a nipple forming of the coolant water flow path. Since the region surrounding such a nipple generally contains hot hydrogen, which could adversely influence the thermocouple, it is the usual practice to seal the thermocouple off from the hot hydrogen atmosphere by a sealing arrangement composed of dacron felt and glass tape. However, it has been found that such seals are not completely effective and eventually permit hot hydrogen gas to contact the thermocouple and to then adversely influence its reading. There is no known way of compensating for such reading errors because the rate of deterioration of a given seal cannot be predicted.
In addition, current systems do not make any provision for simultaneously monitoring coolant water flow. Therefore, if an abnormally high temperature should be detected by the thermocouple, the operator cannot determine whether this is due to faulty generator operation or a blockage or leak in the coolant water flow path.